57pan,
Thanks for posting the reference to Hiatus Campers. I just sent them an email asking if they can replace the pop-up portion of my FWC camper with their hard side pop up top.
The rigid, composite panels they use for the folding walls are made out of fiberglass and plastic. These are by nature waterproof. The core of these panels has a closed-cell foam that has high insulative properties.
I anxiously await their response.
I am motivated by the following.
Our 2007 FWC Keystone has one plastic window in the pop up sideliner portion that has aged, embrittled and cracked. I contacted FWC about repair/replacement of the window and they replied that do not replace just the clear windows on the sideliner, the cost to replace the sideliner is $5572.00 and since one of my front plywood panel is degraded they recommend replacing both of the folding panels, if I replace the folding panels with the sideliner I would not pay any labor for removing and installing the end panels, only the parts. The cost for the two end panels is $1200.00.
Bottom line, a new sideliner with two new end panels installed would cost $6772 plus tax.
I do not know how much the cost is to replace just the end panels since the labor is buried in the sideliner replacement.
I could simply bond a piece of clear vinyl repair material over the cracked window, which won't look great but will solve the problem cheaply and then pay for installation of new lift panels which I will estimate at 2x the cost of the panels themselves which would be $2400.
It will be interesting to find out if Hiatus Campers can create a hard sided pop up retrofit and how that cost will compare (assuming they would do it).
I will post what I learn here.